add connect/disconnect methods

src/repositories/RedisNotificationRepository.ts

@@ -21,6 +21,14 @@ class RedisNotificationRepository implements NotificationRepository {
     this.unsubscribeFromNotificationChanges = this.unsubscribeFromNotificationChanges.bind(this);
   }
 
+  public async connect() {
+    await this.redisClient.connect();
+  }
+
+  public async disconnect() {
+    await this.redisClient.disconnect();
+  }
+
   public async addOrUpdateNotification(notification: ScheduledNotification): Promise<void> {
   }